Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755495Ab3DPNJ6 (ORCPT ); Tue, 16 Apr 2013 09:09:58 -0400 Received: from mail-bk0-f54.google.com ([209.85.214.54]:55419 "EHLO mail-bk0-f54.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754831Ab3DPNJ4 (ORCPT ); Tue, 16 Apr 2013 09:09:56 -0400 Date: Tue, 16 Apr 2013 15:09:51 +0200 From: Ingo Molnar To: Waiman Long Cc: Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , "Paul E. McKenney" , David Howells , Dave Jones , Clark Williams , Peter Zijlstra , linux-kernel@vger.kernel.org, x86@kernel.org, linux-arch@vger.kernel.org, "Chandramouleeswaran, Aswin" , Davidlohr Bueso , "Norton, Scott J" , Rik van Riel Subject: Re: [PATCH 0/3 v2] mutex: Improve mutex performance by doing less atomic-ops & better spinning Message-ID: <20130416130951.GB20961@gmail.com> References: <1366036679-9702-1-git-send-email-Waiman.Long@hp.com> <20130416091259.GC9569@gmail.com> <516D3ADE.9060606@hp.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <516D3ADE.9060606@hp.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1466 Lines: 35 * Waiman Long wrote: > On 04/16/2013 05:12 AM, Ingo Molnar wrote: > >* Waiman Long wrote: > > > >>[...] > >> > >>Patches 2 improves the mutex spinning process by reducing contention among the > >>spinners when competing for the mutex. This is done by using a MCS lock to put > >>the spinners in a queue so that only the first spinner will try to acquire the > >>mutex when it is available. This patch showed significant performance > >>improvement of +30% on the AIM7 fserver and new_fserver workload. > >Ok, that's really nice - and this approach has no arbitrary limits/tunings in it. > > > >Do you have a performance comparison to your first series (patches 1+2+3 IIRC) - > >how does this new series with MCS locking compare to the best previous result from > >that old series? Do we now achieve that level of performance? > > Compared with the old patch set, the new patches 1+2 have over 30% > performance gain in high user load (1100-1500) in the fserver and > new_fserver workloads. The old patches 1+2 or 1+3 only manages > around 10% gain. In the intermediate range of 200-1000, the 2 sets > are more comparable in performance gain. Ok, that's cool! Thanks, Ingo -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/